Negative air ions created by water shearing improve erythrocyte deformability and aerobic metabolism

To elucidate a potential mechanism by which negative air ions improve aerobic metabolism, changes in venous blood lactate levels, pH, erythrocyte deformability, and plasma superoxide dismutase activity and ceruloplasmin levels were examined during a 1-h exposure to negative air ions created by water shearing or corona discharge in nine adult healthy volunteers. The blood lactate level decreased from 1.3 +/- 0.3 to 1.0 +/- 0.2 mmol/l, pH increased from 7.388 +/- 0.025 to 7.417 +/- 0.036, and erythrocyte deformability improved from 37.0 +/- 2.2 to 35.1 +/- 3.0 s, expressed as the mean +/- s.d., when exposed to negative air ions created by water shearing, but did not change when exposed to negative air ions created by corona discharge. Other variables did not change in either exposure. The results obtained suggest that negative air ions created by water shearing improve aerobic metabolism by improving erythrocyte deformability. PRACTICAL IMPLICATIONS: The paper shows that negative air ions created by water shearing method improve aerobic metabolism only during a 1-h exposure, which may be caused by improvement of erythrocyte deformability, but negative air ions created by corona discharge have no effects. A potential mechanism is that negative air ions enter the circulating blood via the lungs and electrons of these ions are delivered to the plasma protein. Why negative air ions created by corona discharge have no effects is considered that water binding does not exist so that the lifetime of these ions is markedly short, by which the ions cannot reach the alveoli of the lungs sufficiently.     

Max-Stretch Reduction for Tree Spanners

A tree t-spanner T of a graph G is a spanning tree of G whose max-stretch is t, i.e., the distance between any two vertices in T is at most t times their distance in G. If G has a tree t-spanner but not a tree (t−1)-spanner, then G is said to have max-stretch of t. In this paper, we study the Max-Stretch Reduction Problem: for an unweighted graph G=(V,E), find a set of edges not in E originally whose insertion into G can decrease the max-stretch of G. Our results are as follows: (i) For a ring graph, we give a linear-time algorithm which inserts k edges improving the max-stretch optimally. (ii) For a grid graph, we give a nearly optimal max-stretch reduction algorithm which preserves the structure of the grid. (iii) In the general case, we show that it is -hard to decide, for a given graph G and its spanning tree of max-stretch t, whether or not one-edge insertion can decrease the max-stretch to t−1. (iv) Finally, we show that the max-stretch of an arbitrary graph on n vertices can be reduced to s′≥2 by inserting O(n/s′) edges, which can be determined in linear time, and observe that this number of edges is optimal up to a constant.     

X-Ray Microanalysis on the Surface and Cross-Section of burning-interrupted aluminum particle and foil in high pressure atmospheres

In order to deduce the burning characteristics of aluminum (Al) particle in solid propellant, a model experiment has been carried out with Al spheres of 3 mm ∼4 mm dia. in the oxidizing atmospheres at elevated pressures. As one of the investigation items, X-ray microanalysis for the burning-interrupted Al spheres was conducted along the straight lines crossing cap-like Al₂O₃ islands attached on unburned Al. It was clarified that, on the way of burning, in the case of Al sphere and plausibly on the burning surface of the particle also, there exist numerous Al₂O₃ islands, large and small, floating on molten Al sea; but even on the sea part, which seemed pure Al only, the surface is covered mostly with Al₂O₃ film. The similar analysis was applied to the Al foils ignited with Joule heating. It was witnessed, however, that contrary to the sphere surface there remains still neat Al in the vicinity of burning-interrupted surface. This fact may introduce low ignition temperature (933 K ∼ 963 K) and high deflagration velocity along the surface (for example. 2500 mm/s, with test piece of 0.11 mm thick, 5 mm wide; 8 MPaO₂ ) with Al foils.     

On the adhesion between Hydroxyl-Terminated Polybutadiene Fuel-Binder and Ammonium Perchlorate. Performance of bonding agents

A simple method to evaluate the adhesive force between solid oxidizer and polymeric fuel-binder is presented. As an illustration, hydroxyl-terminated polybutadiene (HTPB) sticks including several different bonding agents are bonded on ammonium perchlorate (AP) single crystals, and stress-strain history until rupture occurs is obtained by applying uniaxial tensile stress perpendicularly to the adhesion surface. Further, whether each bonding agent reacts with AP or not was analysed with pursuing infrared absorption spectra. The hypothesis that the interfacial adhesive force arises from hydrogen bonding force is proposed.     

Effects of Additives on the Ignition of AP-Based Propellants at subatmospheric pressures

The ammonium perchlorate (AP)-oxidized composite propellants, each of which contains separately copper chromite (CC) as a burning rate adjuster and carbon black (CB) as an opacifier, have been ignited at subatmospheric pressures of argon gas by means of a carbon dioxide laser, and the effects of the additives on the ignition behavior have been studied. It has been found that copper chromite shortens the ignition time especially below 100 torr and that at the same time it enhances the ignitability, i.e., self-sustaining ignition. Carbon black, being an opacifier decreasing reflectivity and increasing radiative absorption at propellant surface, can not be recognized to be an active catalyst in ignition at subatmospheric pressures. The data of differential thermal analysis (DTA) for above specimens have indicated that the maximum exothermic peak temperature is shifted toward a lower one with the increase in CC concentration, the exothermic peak structure becoming sharper. However, CB addition to the basic propellant makes exothermic peaks less distinct. The results of DTA support those obtained from the ignition experiments above.     

A representation method of assembly tasks for dealing with uncertainty

This article proposes a representation method of assembly tasks that enables a robotic system to carry out the tasks under uncertainty. The assembly task is represented by the sequence of contact states and control parameters that are generated by repeated measurements of force sensor outputs with the guide of control sphere conditions. The article describes how the control sphere conditions guarantee the correct transitions of contact states between objects along the sequence of the contact states. Finally the article demonstrates the effectiveness of our representation method by experimental works. © 1998 John Wiley & Sons, Inc.     

Synbiotic promotion of epithelial proliferation by orally ingested encapsulated Bifidobacterium breve and raffinose in the small intestine of rats

We evaluated the effects of Bifidobacterium breve JCM1192(T )and/or raffinose on epithelial proliferation in the rat small and large intestines. WKAH/Hkm Slc rats (4 wk old) were fed a control diet, a diet supplemented with either encapsulated B. breve (30 g/kg diet, 1.5 x 10(7) colony-forming unit/g capsule) or raffinose (30 g/kg diet), or a diet supplemented with both encapsulated B. breve and raffinose, for 3 wk. Epithelial proliferation in the small intestine, as assessed by bromodeoxyuridine immunohistochemistry, was increased only in the B. breve plus raffinose-fed group. We determined the number of bifidobacteria in cecal contents using fluorescence in situ hybridization and confirmed the presence of ingested B. breve only in the B. breve plus raffinose-fed group. This suggests that the ingested B. breve cells used raffinose and were activated in the small intestine, where they subsequently influenced epithelial proliferation. In conclusion, we found a prominent synbiotic effect of encapsulated B. breve in combination with raffinose on epithelial proliferation in rat small intestine but not in large intestine. To our knowledge, this is the first report of a synbiotic that affects epithelial proliferation.     

Cytotoxic effect of endodontic bacteria on periapical fibroblasts

This study was conducted to investigate the effects of sonicated bacterial extracts (SBEs) from anaerobic Gram-negative bacteria on periapical fibroblast obtained from the apical portion of human periodontal ligaments. Porphyromonas endodontalis, Porphyromonas gingivalis, Prevotella intermedia, and Fusobacterium nucleatum were chosen from among the endodontic bacteria isolated from root canals having a periapical lesion and compared in terms of their cytotoxicity. The purpose of this study was to examine which bacteria are involved in the development of periapical inflammation. The anaerobes were cultured under strict anaerobic conditions, and the bacterial cells were then harvested by centrifugation after incubation. The concentrated cell suspensions were sonicated and subsequently centrifuged. An SBE was made of each of the filtered supernatants. Each SBE was added to cultures of periapical fibroblasts. The cell growth and proliferation were measured by the MTT method after 3, 5, and 7 days. The SBEs from P. endodontalis, P. gingivalis, and F. nucleatum inhibited the growth of the fibroblasts, whereas the SBE from P. intermedia did not inhibit it. The SBEs from P. gingivalis and F. nucleatum inhibited the fibroblast growth more strongly than did the P. endodontalis, P. gingivalis, and F. nucleatum may participate in the development of periapical lesions.     

Expression and function of murine receptor tyrosine kinases, TIE and TEK, in hematopoietic stem cells

Two highly related receptor tyrosine kinases, TIE and TEK, comprise a family of endothelial cell-specific kinase. We established monoclonal antibodies against them and performed detailed analyses on their expression and function in murine hematopoietic stem cells (HSCs). TIE and TEK were expressed on 23.7% and 33.3% of lineage marker-negative, c-Kit+ and Sca-1+ (Lin- c-Kit+ Sca-1+) HSCs that contain the majority of day-12 colony-forming units-spleen (CFU-S) and long-term reconstituting cells, but not committed progenitor cells. Lin- c-Kit+ Sca-1+ cells were further divided by the expression of TIE and TEK. TIE+ and TEK+ HSCs as well as each negative counterpart contained high proliferative potential colony-forming cells and differentiated into lymphoid and myeloid progenies both in vitro and in vivo. However, day-12 CFU-S were enriched in TIE+ and TEK+ HSCs. Our findings define TIE and TEK as novel stem cell marker antigens that segregate day-12 CFU-S, and provide evidence of novel signaling pathways that are involved in the functional regulation of HSCs at a specific stage of differentiation, particularly of day-12 CFU-S.     

Hardware neural network models of CPG and PWM for controlling servomotor system in quadruped robot

This paper discusses the pulse-type hardware neural networks (P-HNNs) that contain a central pattern generator (CPG) and a pulsewidth modulation (PWM) servomotor controller and the application to quadruped robots. The purpose of our study is mimicking the biological neural networks and reproducing the similar motion of the living organisms in the robot. The CPG of the living organism generates the walking rhythms. We mimicked this CPG by modeling the cell body and the synapse of the living organism. The developed CPG composed of the P-HNN output four pulse signal sequences and the four outputs are introduced to each leg of the quadruped robot. On the other hand, the angle of the servomotor is controlled by the PWM. The PWM is obtained by modeling the axon of the living organism. The CPG and the PWM servo control system perform the walking motion of the quadruped robot. Moreover, the gate pattern change of quadruped animals is reproduced by these P-HNNs.